The present invention relates to an apparatus for measuring the internal stress of a strip during the rolling process thereof, which apparatus is employed for adjustment and control of pressure application in a rolling mill.
A conventional rolling mill has the shortcoming of generating non-uniform internal stress from place to place in each strip, such as in aluminum strips, in the course of the rolling process, due to slight changes in the gap or pass between the work rolls, caused, for instance, by heat generated during the rolling. The non-uniform internal stress generated in the rolled strip has a variety of adverse effects on the working of the rolled strip following the rolling process.
Therefore, it is necessary that the internal stress generated in the rolled strip be continuously measured during the rolling process, and that the pressure applied to the strip by the work rolls be appropriately adjusted in accordance with the feed back signal indicating the measured internal stress.